1. Field
Exemplary embodiments of the present disclosure relate to a display device having a built-in touchscreen and a driving chip, a circuit film, and a chip-on-film (COF) type driving circuit included in the display device.
2. Description of Related Art
In response to the development of the information society, demand for a variety of display devices for displaying images is increasing. In this regard, a range of display devices, such as liquid crystal display (LCD) devices, plasma display panels (PDPs), and organic light-emitting display devices, have recently been used.
Many display devices provide touch-based input interfaces enabling users to intuitively and conveniently input data or instructions directly to devices, rather than using conventional input systems, such as buttons, a keyboard, or a mouse.
To provide such touch-based input interfaces, the ability to sense a touch made by a user and accurately detect touch coordinates is required.
In this regard, in the related art, a touch sensing method selected from among a variety of methods of touch sensing, such as resistive touch sensing, capacitive touch sensing, electromagnetic induction, infrared (IR) touch sensing, and ultrasonic touch sensing, is used to enable touch sensing.
In such a variety of touch sensing methods, capacitive touch sensing is commonly used, in which a touch electrodes are disposed on a touchscreen panel (TSP) to detect a touch and touch coordinates based on changes in capacitance between specific touch electrodes or changes in the capacitance between specific touch electrodes and a pointer, such as a finger.
A range of attempts at disposing a touchscreen panel including electrodes in a display panel have been made in order to facilitate the fabrication of display devices and reduce the sizes of display devices.
However, a display device having a built-in touchscreen must be provided with a source driving circuit driving data lines to display images and a touch driving circuit driving touch electrodes to enable touch sensing, in which the source driving circuit and the touch driving circuit are separately provided.
This may increase the number of components of driving circuits required. In particular, the number of components of driving circuits may be increased further when the size or resolution of a display panel increases.
Therefore, in the development of a display device having a built-in touchscreen, the number of components of driving circuits may be significantly reduced by integrating a source driving circuit with a touch driving circuit.
A source driving circuit is typically embodied as a chip-on-film (COF) type circuit to be connected to a display panel. When the COF type source driving circuit is integrated with a touch driving circuit, touch sensing errors may occur. Such errors do not commonly occur when the touch driving circuit and the source driving circuit are provided separately, and the cause thereof has not yet been identified.